Process and mechanism fob dividing



July 4, 1939. K. DAVIS Re. 21,136

PROCESS AND MECHANISM FR DIVIDING INTERMIXED MATERIALS Original Filed April l5. 1922 5 Sheets-Sheet l July 4, 1939- K. bAvls Re. 21,136

PROCESS AND MECHANISM FOR DIVIDING INTERMIXED MATERIALS original Filed April 15,'1922 Z INVENTC'JR y g A TORNEY July4, 1939. K DAVIS Re. 21,136

PR-OGESS AND MECHANISM FOR DIVIDING INTERMIXED MATERIALS Original Filed April l5, 1922 5 Sheets-Sheet 4 0 5b [iN/VE O Ressued July 4, 1939 PROCESS AND MECHANISM FOR DIVIDING INTERMIXED MATERIALS Kenneth Davis, Punxsutaw'ney, Pa., assigner, by mesne assignments, to Richard Peale, Morton F. Locke, and William B. Oakes, trustees Original No. 1,786,738,dated December 30, 1930, Serial No. 553,250, April 15, 1922. Application for reissue August 10, 1938, Serial No. 224,228

24 Claims.

The invention relates to a novel mechanism and process for separating intermixed, divided materials of different specific gravities, and more especially to a novel mechanism and process wherein `air under pressure and vibratory action, together with gravity, are employed; the novel features of the invention being pointed out hereinafter in part and in part being obvious herefrom or to those skilled in the art.

The invention consists in the novel parts, constructions, arrangements, combinations, improvement, steps and processes, herein described.

The accompanying drawings, referred to herein, and constituting a part hereof, illustrate one embodiment of the invention, and together with the description serve to explain the principles thereof.

Of the drawings:

Fig. 1 is a central longitudinal, vertical section, 20 through a separating unit, embodying the invention;

Fig. 2 is a transverse, vertical section taken on the line 2 2 of Fig, 1, looking in the direction of the arrows;

2 Fig. 3 is a transverse vertical section, taken substantially on the line 3 3 of Fig. 1, looking in the direction of the arrows;

Fig. 4 is also a transverse vertical section taken substantially on the line 4 4 of Fig. 1, looking in the direction of the arrows;

Fig. 5 is a side elevation, with the central part broken away, of va separating unit with its mounting, and its vibrating and air pressure mechansrn, and its material conveying devices and is taken looking at Figs. 1 and 7 from the front.

Fig. 6 is a fragmentary view, partly in elevation and partly in section, o-n the line 6 6 of Fig. 5, showing a part of the air pressure mechanism;

Fig. 7 is a view corresponding to Fig. 1, but 40 showing the separating unit, more Or less diagrammatically, in inclined position, and with the intermixed materials in process of separation;

Fig. 8 is a transverse, vertical section, taken substantially on the line 8-8 of Fig. 7, looking in the direction of the arrows, and showing more or less diagrammatically the process of separating the materials;

Fig, 9 is a fragmentary elevation corresponding to the upper left-hand part of Figs. 1 and 5, 50 but showing a modified form of the separating unit walls;

1G is a fragmentary elevation corresponding to the upper right-hand part of Figs. 1 and 5, and showinrr a mcdied form of this part of the separating unit walls;

Fig. 11 is a transverse, vertical section, taken If.:

substantially on the line Il ll of Fig. 10, looking in the direction of the arrows;

Fig. 12 is a side elevation, on a diminishedscale, of a separating unit, showing a modified form of delivery chute, adapted for separating the different sizes of a separated material.

Fig. 13 is a transverse vertical section, taken substantially on the line |3 |3 of Fig. 12, looking in the direction of the arrows; f

Fig. 14 is .a top plan of a separating unit, on a hand end of Fig. l, but showing one part in hor- I..

izontal section;

Fig. 18 is taken on line |8 |8 of Fig. 17, showing one side of the end of the unit in vertical transverse section and the other side in elevation; and

Fig. v19 is a fragmentary vertical longitudinal y section of a modified form.

The present invention, in certain aspects thereof, is an improvement on the invention of my co-pending application Serial Number 541,123,

filed March 4, 1922, Patent No. 1,782,392, dated November 18, 1930. In other aspects thereof, however, the invention is independent of my said co-pending application, and is capable of independent use or of use in separating units differing therefrom in greater or less degree, both in structure and in manner of operation.

The term divided as employed herein is conveniently used to signify materials which are in relatively small parts, portions, or particles, such as, broken, or crushed materials, or granular' 'or pulverulent materials, as distinguished from materials in large masses. An example of such materials, and one with which the present invention has proved very successful, is mixed coal and rock or slate, with which is also mixed at times the material known as bone or bony (a combustible material but having a very high ash content).

It is customary to size the coal and other intel-mixed materials very closely, by screening or otherwise, and to then subject such sized materials to the action of a separating apparatus. This invention is adapted successfully and eiiiof the intermixed divided materials, preferably relatively long and narrow in form and of considerable depth, is subjected to the separating action of a flow of air under pressure. This separating action is preferably aided and expedited by very rapid and short, but forceful vibrations of f the bed of materials, the vibratory movement being preferably bi-directional, that is, it is both longitudinal of, and transversely to, the bed of v materials in the separating unit. -The forward' and downward inclination usually imparted to the unit involves gravitational action therewithi' The intermixed materials are rapidly separated and thus are gradually but also very .rapidly stratified. The heavy material such as the rock, under the action of the agencies, movements and forces acting thereon, sinks and then fiowslongitudinally forwardly along the bottom of .the bed, and is discharged from the lower forward end thereof. 'Ihe lighter material, at the same time, under the operation of these agents, forces and movements, seeks and flows along the upperpart of the bed, and here is subjected to such of these agencies and influences as will cause the discharge of the clean and separated lighter material, such as the coal, from the top, and preferably over the sides of the unit. I

By the present invention, the stratifying'and separating action of the air at the'frear or entrance of the separating unit is changed from that disclosed in my said copendingapplication, as is also the nal back-pressure separatingac'- tion of the air "at thev forward ordischarging end of the unit. Also the movement and .back pressure of the heavier material, such as therock, is likewise different and is differently controlled from that of my preceding invention, already referred to, together with other novel `Afeatures which will be first set forthin connection `with the following detailed description of,Y theinvention. It will be understood that the foregoing broad and general description, and the followingl detailed description as Well, are exemplaryandexplanatory, but are not restrictivev of the invention; and that the statement of the principles of operation of the invention is correct and adequate as at present advised from observation of, andy experimentation with, the invention in practical operation, but that the invention is not necessarily limited thereto or thereby.Y`Uv

Means are provided by-the inventionfo'rfsup- Yplying the intermixed divided materialsto .the

cleaning and separating unit automatically .,at

.a rate just sufcient for the capacity o f theunit,

that is, at the highest rate of total andeffective ,separation accomplished by the Vunit' under. the

particular conditions of operation, suchas `the physicalcondition of the intermixed, materials,

`the-.nature thereof, the size,- or variations in size,

therelative specific gravities (1f-:the intermixed materials, or other conditions.

`As embodied, a generally vertically` disposed hopper I is provided, open at-,the top, and'pref.- erably'having some or all of its sides-inwardly anddownwardly inclined, asishownyinjigs, l

`and fi,v thev wallsofthe hopper beingconstructed preferably of foraminate or cribriform material.

.of the material at the bottom of the hopper is avoided, and the material is always free to fiow forward into the separating unit as rapidly as the unit'cantake care of it. The rear wall 4 of the -hopper is shown inclined, while the front wall 5 is Is hown vertical and wholly or in part solid for purposes Vto be, later described.

The air pressure is preferably utilized for pre- Vlii'ninarly driving Aout the dust from the inter- `-Irxiiedmaterials, asdescribed in my previously i'lled and co-pending application already referred to; the Vair for this purpose passing upwardly and backwardly through the part 'I of the air pervious bottom I5, the slide 8 being utilized to regulate and,'govern'this upward ow and pressure of the air for' cleaning out dust. Brackets I9 resting on side .plateZIl holdthe hopper in position, the plates 20 Ybeing integral with or resting upon the supporting'railsI 30 and 3| for the unit (later described) 'Means are also provided for regulating the flow or,.supply .of the intermixed materials into the separatingunit and, as shown, the size of the open throat' or passageway 9 at the bottom and forward end of the hopper'is governed or controlled byv a vertically movable or adjustable slide I0, moving slidably on the hopper wall 5, and eX- tending the widthof .the opening 9. This slide is movable within a guiding strip Il, fastened to the hopper wall, and having a slot I3 through which passes a clamping bolt I4, which also passes through the-,hopper wall, to hold the slide I in its adjusted vertical position.

.The separating unit is preferably of relatively Vlongfand narrow dimensions, and is designed to hold a relatively deep bed of materials, at first intermixed, then gradually but rapidly and com- {pletely stratified and thereby separated, discharging the heavy material downwardly and the. lighter material from the upper part of the bedi the heavy material being also preferably discharged forwardly and the lighter materials transversely. v4 v 'Meansare provided by the present invention for subjecting theintermixed materials on their .entry into the separating unit to such an air pressure and .air current action, concomitant with such1 a control of the material at this time aswillfinsure, notonly a rapid and complete stratification or separation of the intermixed material, but will secure these desired results with intermixed materials which are of relatively widelyvarying sizes, that is, with materials which have not been closely sized in the usual manner.

In the embodiment form of this means, there is provided at the back or entrance end of the separating unit, in conjunction or cooperation with air pressure pervious bottom I5, which may be of closely woven wire mesh, preferably varying in size to ,suit `different sizes of material, a flud pervious hoodfor closure (Figs. 1 and 2) having sidewalls I5 and I'I abutting on the pervious bottom I5 and extending upwardly therefrom, the sidewalls being integral or continuous and forming an'arched top I8, constituting a complete but fluid pervious closure at this end or portion of the separating unit. The solid side walls of the unit are preferably entirely discontinued at this portion of the unit. Also the forward end of the hood is preferably left open.

Thus, the action of the air at this part `of the separating unit and the separating process can be directed, controlled and regulated irrespective of maintaining the materials (which are not yet completely stratified and thereby separated) at any particular level of the unit or driving the air in only the Vertical direction or through a given depth of material.

It is found in practice, especially with some materials and with some physical conditions of intermixed materials, and particularly where some portions of the intermixed materials are relatively finely divided with respect to others (that is, where the materials vary greatly in size), that to use an` air current which will effect a desired rapid stratification and separation of the larger particles of the intermixed materials, will drive the smaller particles of the intermixed materials Yentirely through the bed of materials. The pervious restraining hood, however, throws thesev materials back upon the bed and by reason of the partially accomplished stratication and the vibratory movement and the gravitational action, these smaller pieces of material will gradually stratify with the larger portions before leaving, or just after-leaving, the forward end of this pervious hooded portion of the unit.

The relative length and other dimensions of the various portions of the unit may be experimentally varied as may be found most efficient with different kinds and conditions of intermixed materials. The general proportions shown in Figs. 1 to 3 and 16 to 18 has proved eflicient and satisfactory with steam coal intermixed with slate and bone, varying considerably in size far beyond the ranges produced by the usual screening or sizing. It will be clearly understood, however, that thel invention is in nowise limited by these proportions.

The separating unit just forward of this pervious hooded portion, which has just been described, has preferably solid sidewalls 2B and 21 of board, sheet metal or the like, which are connected to the bottom and general structure, as shown in Fig. 3, the sides resting upon the perforated bottom I5, which in turn rests upon the sidewalls 28 and 28 of the air chamber. The side rails or strips 3U and 3l unite this entire structure together, as shown in Fig. 3, these rails also serving to support the unit upon its vibrating frame as shown in Fig. 5 and later described.

The supporting and structural strips 30 and 3l are preferably cut down at the sides of the hooded portion just described, so as to give free egress to the air through the whole depth of the bed of mixed materials, and as shown in Fig. 2, thin retaining strips 32 and 33 are laid upon the turned out edges of the perforate sidewalls I5 and I1 to fasten them in place against the bottom l5 and within the strips 3U and 3|.

Means are also provided by the invention for effecting additional strong air pressure action at the forward end of the separating unit to insure the final separation of the last intermixture, or possible intermixture, at the juncture of faces of Contact of the superior and inferior strata of the now nearly completely separated materials. In certain cases, dependent to a great degree on the nature and physical condition of the material an absolute and complete separation is impracticable. A small portion of still intermixed materals maybe discharged together to be returned back into the mixed materials to pass again through the separating unit.

As embodied, the sidewalls 26 and 21 of the separating unit, at their forward end, are inclined or curved upwardly, as shown at 34 and 35 in Figs. 1 and 3, whereby the level of the tops of the walls relatively to the general level of the bed of material is gradually increased in the forward direction. In connection therewith a similar perforate hood is provided, comprising upwardly extending sdewalls 3E and 31 continuous with and forming an intermediate arched top 38. The bottom edges of the side walls are turned outwardly and rest upon the top of the parts 34 and 35 of the walls of the unit, being held thereto by retaining strips 39 and 40. The hood just described is preferably open at its rear end, that is, looking backwardly along the body of the unit.

Preferably the iiuid pervious bottom of the separating unit at its forward and downward end, and in conjunction with the structure and mechanism just described, is more freely pervious to the passage of the air under pressure, and for this purpose preferably this part 42 of the bottom I5 is of coarser mesh than the rearward portion of the bottom.

in connection with the structure just described, there is preferably provided a stratum regulating and supporting member, such as a vertically extending plate 48, extending the full width within the high, forward part 34 and 35 of the sidewalls of the unit, the bottom end thereof being positioned above the bottom far enough to permit passage of the largest fragments or pieces in the bottom stratum, that is of the layer of separated heavier material. At the bottom of this plate 48 is a horizontally disposed, forwardly extending plate 43, likewise extending entirely across between the unit walls. These two plates are vertically positionable as desired, and are preferably positionable together, and for this purpose Connecting side plates 5i] are provided, having slots 5I therein through which project bolts 52, respectively, which likewise project through the unit sidewalls to clamp the structure in the desired position.

Means are likewise provided by the invention for regulating the height and back-pressure of the inferior stratum of the now separated heavier material, this being preferably effected by offering a predetermined or regulated, but yielding pressure against its discharge from the bottom and forward end of the unit, this means preferably cperating in conjunction with the vertically positionable plates 48 and 49.

As embodied, a swinging gate 56 is hinged at its upper end on a transversely disposed cross rod 51, carried in brackets 58 and 59, which are mounted on the unit sidewalls. At its bottom end the gate 5B is provided with an outwardly extending shelf or rod or like support 6U upon which a weight or weights 6I are placed, as upon a pin 52. ment serves to keep the gate closed on the forward end of the inclined unit up to a certain pressure of the heavy stratum and when this pressure is exceeded, permits the gate to swing outwardly to discharge a certain amount of the heavy material, such as the slate or rock.

The manner of operation of the mechanism just described is substantially as follows:

The action of the upper and rearward part of the separating unit in connection with the preliminary stratification of the intermixed materials has already been described. The now com- This construction and arrangepletely or'nearly completely stratied materials move forwardly and downwardly from the rear hooded part of the unit between the walls 26 and 21, and tend to pile up against the plate 48.

If in the varying conditions of stratication, any of the lighter material, such as the coal, tends at any time to sink below the level of the plate 49 (this plate being adjusted to prevent this under average conditions with the particular intermixed materials under the particular physical conditions), the strong upward and backward air pressure at this point will drive these lighter materials backwardly and upwardly in the separating unit.

It will be noted that the plate 49 and the gate 56 close the forward end of the unit against the travel and pressure of the air. The result is that the lighter material, such as the coal, is

thro-wn energetically and sometimes violently,

upwardly and backwardly into the hooded portion 38, and therewith possibly some of the smaller particles of the heavier material, such as the rock. The pervious hood permits any desired force of this backward and upward air pressure to be utilized irrespective of the height of the side walls of the unit.

When this iinal remnant of the intermixed materials is blown upwardly into the hood, the lighter material, such as the coal, is also blown backwardly, that is, toward the left in Fig. l, into the coal-in the intermediate portion of the separator unit. The heavier material, such as the rock on the other hand, will fall backwardly toward the plate 48 and in the continuance of this process will gradually settle down into the inferior stratum of heavier material, and be discharged through the gate 56. The lighter material such as the coal, on the contrary, will be thrown backwardly and will gradually pass outwardly over the sides 26 and 21 of the unit, completely clean and separated.

It will be found in practice, especially with such materials as have already been referred to;

that there is a strong tendency of the larger particles of the superior stratum, that is, the lighter material, such as the coal, to travel toward the forward end of the unit, while the smaller particles of the coal to work more quickly to the upper part of the stratum of coal, and to be discharged over the tops of the sidewalls 28 and 21 just forwardly of the hood I8, the discharging particles or pieces increasing in size gradually forwardly along the separating unit. There is thus not only a discharge of the clean coal over the tops of the sidewalls but there is also a sizing operation, considered longitudinally and forwardly of this part of the separating unit. Means for taking advantage of this feature of the invention in maintaining separate and in conveying away the sized material will be later described.

A brief description will now be given of the general structure of the entire separating mechanism, together with the vibrating mechanism, the conveying devices for the separated materials, and the air pressure means.

The air pressure chamber has the sidewalls 28 and 29, already described, and has a relatively vertically dispo-sed rear wall 10 and a downwardly and rearwardly extending front wall 1|. This chamber terminates usually together with a plurality of other units, in a header 13, having a flexible connection 14 with an air pressure supply pipe 15. This is supplied with either a continuous or intermittent air pressure from a bellows,

blower, or other suitable air-pressure generator.

The separating and cleaning units either singly or in a battery `or group, are supported by means of the strips 30 and 3| upon a vibratable frame, having cross reaches 16 and 11 and side reaches 18 and 19. This frame has downwardly. extending pins contiguous to its four corners, about which are coiled helical compression spring 8|, seated respectively upon pins 82, projecting upwardly from the stationary supporting fra-me.

The transverse vibrating means comprises a magnet 86, mounted upon a support 81, carried by the cross reach 88 of the stationary frame. The armature piece 89 for the magnet is fixed on the crossY reach 16 of the vibratable frame. Pins 90 are xed in thestationary frame, and have screw and nut adjustments 9| to vary their length. They cooperate respectively` with pins 92 in the vibratable frame to regulate the amplitude of the resilient transverse vibration.

The means for effecting the vibration longitudinally of the separating units comprises a magnet 98, mounted upon a support 99, carried on the cross reach |00 of the stationary frame. I'he armature piece |0| of the magnet is mounted on the cross reach 11 of the vibratable frame. Pins |92 have screw and nutadjustment |03 to regulate the amplitude of the longitudinal vibration, these pins cooperating, respectively with pins |04 mounted on the vibratable frame.

Means are provided for varying the degree of inclination of the units, and as embodied, legs |06 are pivotally connected at |01 to the side reaches |08 and |09 of the stationary frame. Near the other end of these side reaches, legs I|0 have a bolt and slot connection with the side reaches, which gives the necessary or desired regulation of the inclination of the units.

In Figs. 1 and 5 and 'lare shown a general form of conveying means similar to that'shown in my co-pending application. Chutes IIB are shown attached to the sides of the separating units to receive the lighter material, such as the coal, discharged over the topsof the sides thereof, a belt conveyer receiving the materials from the chutes and conveying it away.

For the heavier material, such as the rock, a short chute ||8 is shown fixed to the supporting strips 30 and 3| for the units, which ychute receives the rock discharged through gate 58. The chutes ||8 discharge into chutes ||9,.supported on the stationary frame and on legs |20. The chutes ||9 discharge onto beltconveyers |2|.

Referring now to the embodied form of conveying means for maintaining separately the sized separated lighter material, such as the coal which, as previously described, is discharged sized to a greater or less degree over the tops of the sides of the separating unitchutes kare provided (Figs. 8, l2 and 13) at either side of, and extending along practically the entire discharging length of, the separating unit. This chute structure has transversely disposed, longitudinally spaced apart portions or separating walls |26, |21, |28 and |29, extending across from the outer chute wall |25 to the respective side wall of the separating unit. The compartments thus formed along each side of the unit open, respectively, into separate chutes |30, |3| and |32, extend downwardly to corresponding endless conveyers |33, |34 and |35 which convey away the sized, separated and cleaned lighter material. In case there is a relatively small remnant of still unseparated materials, such as coal and bony it may be discharged through chute |29 into conveyor |35 and ycarried back to be again subjected to the separating action.

In Figs. 10 and 11 the sidewalls `264i and 21a. of the separating unit are shown vertically adjustable by suitable means, such as bolt and slot connections |36 and |31, whereby the height .of the sidewalls may be varied as may be desired or required with materials of different kinds, in different physical conditions or, of different sizes. Thus the thickness of the bed of material'may be regulated with any desiredde'gree of exactness and nicety.

In Fig. 9 the sidewalls 26 and 21 are shownas extending backwardly and` downwardly inclined along the rear hooded portion I8, thereby modi fying to a corresponding degree the action of the air pressure in the preliminary stages of the stratification. The extent and degree and location, and the form as well, of these parts of the unit sidesmay be varied as may be found expedient, desirable or efcient with different kinds or sizes of intermixed materials, and with such materials in different physical states or conditions.

In Fig. 14, the separating unit is shown of varying width, and as at present advised, and in some cases and with some materials and under certain physical conditions thereof, itI is advantageous to have the unit of gradually increasing' width towards the forward and downward end thereof. In certain cases and with certain materials or conditions thereof the reverse may be found advisable. The eiiciency and desirability of such variations in form may be readily determined by observation with particular materials and under particularf'czonditions and availed of while realizing the -chief advantages of the invention and employing its principles.

In Fig. 15 is shown diagrammaticallyan arrangement wherein the floating plates |48, |4| and |42 are employed, the plates' |40 and |4I being adapted to float on top of the bed of materials, being preferably free "to move 'in the vertical direction but restrained' from lateral movement. Plate |42 "may be .pivotedrpat'its junction with member 48'. In.' operation, the floating plates |40 and 4|, floating upon the air current or body create a back pressure, and when this pressure is exercised permit a portion thereof to escape at either side" and therewith effect an outflow of lighter separated material. This construction also causes thejair tov travel in a current longitudinally and forwardly of the bed and regulates the air pressure" to jus-t the right degree to effect the gradual discharge of the lighter ymaterial over the edges ofthe unit, and prevents violent and uncontrolled action of the air through the mass of material. Any light-v er material which may escape `discharge and pass on beyond the plate 14|, is met by a back air pressure caused by the hinged plate |42 cooperating with the member 48tof deiiectA forwardly moving air currents. .The back air pres-'- sure so generated cooperates withv the upwardly moving air pressure to force any remaining lighter material over the sidesof'the unit. It will be found usually, howevenunder ordinaryc'onditions, that these plates will not .be fnece'ssary, although they will be found helpful and increase the efficiency in certain, cases. j i

In Figs.r 16, 17 and 18 a Adifferent form of construction of the forward end of the separating unit is shown. Therein the forward end of the unit is closed by a wall |46,` preferablyv perpendicular to the airvpervious bottom I5, and inclined inwardlyand backwardly from the two sidewalls 26 and 21 of theunit to the central part thereof as shown best in Fig. 17. This wall |46 thereby constitutes a closure for the front and lower end of. the unit, sloping or inclined downwardly and outwardly from the central line Vor axis of the. unit toward the side walls thereof.

In both of the side walls 26 and 21 immediately rearwardly ofthe inclined end wall |45 and at the bottom of the side walls are two discharge openings |41 and |48, which occupy only a part of the'height of the respective side walls, as best appearslfrom Figs. `16 and 18. The heavier separated material in this case is discharged through these openings l'll and |48 in the bottom parts of the forward ends of the side walls 26 and 21 of the units, the material passing downwardly 'and' outwardly toward and through these openings, along and as directed by the inclined wall Means are provided for producing a regulable `back pressure, or for effecting a yielding discharging pressure on the discharging material at the side Vopenings |41 and |48, and thereby and therefrom. a. backward and upward air pressure or air blast through the bed of material. As embodied, there are provided, projecting outwardly, forwardly and downwardly from the side walls of the unit two short chutes |53 and |54, the bottomsll and |58 of which, in accordance vwith one Y feature of the invention, are preferably extensions of the air pervious bottom of the unit. The chutes', accordingly, are located over i corresponding extensions |5| and |52 of the air pressure chamber 23 (as best appears from Figs, 17 and 18) their bottoms |48 and |50 being of wire meshl or other air pervious material. Thereby the air under pressure in the air pressure chamber 28 is also forced upwardly through the floors |48 and |50.

These discharge chutes extend outwardly a short distance, and preferably with the same di- 'rectionof inclination as the wall |46. The chute |53 has side walls |55 and |56, the wall |56 being conveniently a continuation of the end wall |46 ofthe units' At its front end, chute |53 has av transversely disposed, upwardly extending curb orlip |512` extending across the chute from one vside wa-ll to the other.

The-:construction of the other chute |54 is the same -or similar, this chute having side walls |59 and |68,"and the end curb or lip IGI, similar or the same in construction as those on the other side "of the unit.

' -Thefurther and additional structure for causing the regulable back air pressure or air current in thisA lembodied form comprises loose or floating plates |53 and |54, respectively, which fit loosely within the chutes |58 and |54', as best appears frorri-lig.l 18. Suitable guiding means are' provided'therefor, and as embodiedthe plates `|63` and` 1154 are preferably centrally apertured, and-guidingpins 'lrand |61, respectively, are xedat their'end's in the bottoms of the chutes and in enclosing top plates or covers |68 and |69, respectively. These covers connect with the top edgesfof the chute side walls and of the side Iwal1s-'=o'ftlie-unit as will be clear from Figs. 17 VAa'nd 1S but leave an open discharging space at the forward lend of the respective chutes above the curbs: or lips |51 andll.

The loose or floating closures or plates |63 and j|64` whenA` they sinkv to the level of the lips or curbs |51 and 16| vpractically close the discharge 'orifices |41 andvv |48, and when they rise above the top edge of these lips or curbs I 51`1and l|6l they leave these discharge orifices free for the discharge of the rock or other heavier material.

The two chutes |53 and |54 discharge, respectively, into conveying chutes 14 and |15, .which may conveniently empty into the chute Ill or into any other suitable or'convenient device or means for receiving the discharged rock orV other' heavier material. This chute structure shown at each side in Fig. 17 may be generally similar to that shown in Fig. 12, and already described` In Fig. 19 a slightly modied form is shown wherein the pervious hood 38 is provided at the forward end of the unit, andthe arrangement is substantially the same as shown in Fig. 7.

'Ihe manner of operation of the mechanism just described will be generally understood from what has already been stated. In the modified form of Figs. 16 to 19, the heavier material, through the action of the stratifyingandseparating process, settles at the forward and bottom end of the unit, and tends toV pass outwardly through the discharge openings |41 and |46. However, owing to the curbs |51 and |6I, the free outward flow of this heavier material is impeded. and the floating plates |63 and |64 practically close the chutes. Consequently a. strongv upward and backward air pressure and airy current is produced, which will drive upwardly and backwardly any pieces of particles of the lighter material which may have progressed downwardly to this point, the particles moving upwardlyl and backwardly in the general manner already` described, and nally beingdischarged over the side walls 26 and 21 oi the unit. Should any of the smaller particles of the heavier material be` carried or blown backwardly therewith, these will fall again near the end wall |46 and willfgradually work down towards the dischargey openings |41 and |48.

As the heavier material collects and the layer or stratum increases, the air pressure will force the plates |63 and |64 upwardly past the curbs |51 and |6|, and the rock will be discharged into the chutes |14 and |15. As the pressure decreases, and the amount of heavy materialbecomes less, the plates |63 and |64 will againdrop downwardly and will again close the openingsat the curbs or lips |51 and |6l. Thus the desired backward air pressure and separating. air current are effected and maintainedv while the mechanism automatically operates to discharge the accretions of rock or other heaviermaterial and then returns to its former positionI or condition. Y

From all the foregoing, it will be. understood that a mechanism and process has been provided realizing the objects and advantages herein set forth, together with other objects and advantages; and also that departures may bemade from the exact structure and steps or V'procedure shown and described without departing zrom.v the principles of the invention and without sacrificing its chief advantages.

What I claim is:

1. A mechanism for separating intermixed divided materials including in combinationfmeans for maintaining a bed of the materialameans for subjecting the rearward portion of the bedtu the action of air preure currents in a plurality of directions and for subjecting a more forwardly part of the bed only to air pressure currents upwardly therethrough to progressively stratify and separate the materials and meansfor continuously discharging the separated materials at different points bythe" action of the air and the motion of the table.

2. A'" mechanism for separating intermixed divided materials including in combination means for maintainingabed of' the materials of substantialdepth inl which the materials move along thebe'd 'in the same general` direction, means for subjecting the rearward portion of the bed to the action of'air pressure currents in a plurality of directions and for' subjecting an intermediate part ofthe bedy toair pressure currents only upwardly therethrough and for subjecting the forward portion of the bed to air pressure currents in a plurality of directions including backwardly, and means for continuously discharging the separated materials at diiierent points by the action ofthe' air and the motion of the table.

3. A' mechanism for separating intermixed dividedmaterials including in combination means for maintaining, aA bed of the materials in which L the' light andi heavy materials iiow in the same direction', means for subjecting the materials to the'action of air pressure currents, means located at the rearward and at the forward portion of the bed for maintaining the materials on the bed against the .displacing action of the air currents and" means. fork concurrently and continuously discharging' the lighter and heavier materials fromdiiierent'parts ofrthetable.

4. A mechanism for separating intermixed divided materials including in combination means for maintaining arelatively long, narrow and deep bed of the materials in which the light and heavy materials ilow'in the same direction and progressively stratify, means for subjecting the rearward'portion of the bed to the action or air pressure currents in a plurality of directions and for subjectingan intermediate part of the bed to air pressure currents only upwardly therethrough and 'for subjecting the forward portion of the bed .to airpressure currents in a' plurality of directions including backwardly, and means for continuously discharging the separated materials at differentpoints by theaction of the air and the motion of 'the.table.

5. A mechanism forseparating intermixed divided'fmaterials including in combination means' for maintainingv a bed 'of 'the materials, means for subjecting the rearward'portion of the bed to the action of air pressure currents in a plurality of directions andV` for subjecting an intermediate part of the bed .to air pressure currents only upwardly therethrough and for subjecting the forwardportion of 'thefbedto air pressure currents in aplrality of directions, and means for concurrently vibrating the bed` both longitudinally andr vertically.

6. A mechanism for separating intermixed'divid'edmaterials including in combination means yfor maintaininga bed ofthe materials in which the light'andlheavy materials flow in the same direction, means for subjecting the rearward portionofthe bed to the action oi air pressure currents. in a plurality of 'directions and for subjectingfa more forwardly part ofthe bed only to air pressure. currents upwardly, therethrough to stratify. andv separate the materials, and means for dischargingv the. separated heavier material from the bottom and forwardl end of the bed.

'1. A mechanism for separating intermixed divided materials includingV in combination means for maintaining abed .ofthe materials in which the light andheavy materials flow in theA same directionm`eansfor 'subjecting theY materials to the action of 4`air pressure currents, means located at therearwarcl portion of the bed' for maintaining `the materials in the rear of the bed against thev displacing action of the air currents, and means for substantially continuously discharging the separated heavier material from the bottom and forward end of the bed, and means for laterally discharging the separated lighter material from the top of the bed.

8. A mechanism for separating intermixed divided materials. including in combination means for progressively stratifying and separating the intermixed materials including means for maintaining a bed of the materials having an air pervious bottom and sides partly air pervicus and partly air impervious, and means for forcing air under pressure through the pervious bottom.

9. A mechanism for separating intermixed divided materials including in combination means for progressively stratifying and separating the intermixed'materials including means for maintaining a bed of the materials having an air pervious bottom and sides partly air pervious and partly ,air impervious lengthwise thereof, means for transversely discharging the separated lighter material from the top stratum, and means for forcing air under pressure through the pervicus bottom.

10. A mechanism for separating intermixed divided materials including in combination means for stratifying and separating the intermixed materials including means for maintaining a bed of the materials having an air pervious bottom and sides partly air peivious and partly air impervious, means for forcing air under pressure 'through the pervious bottom, and a hood restraining the material from being thrown clear of the bed by the air current.

11. A process for separating intermixed divided materials, comprising subjecting a downwardly inclined bed of intermixed materials to currents of air flowing upwardly therethrough and to vibration, for causing the materials to move along together in the same general direction and to stratify progressively, and screening a given area at the top of the bed for allowing the escape of the air and for preventing the escape oi solid materials, the ultimate separation being effected by a spilling over of the lighter material from the top stratum.

l2. A process for separating intermixed divided materials comprising maintaining a continuous bed of intermixed materials of substantial depth upon and progressing it along an air-pervious table, having a substantially continuous surface, gradually and progressively stratiiying and separating the intermixed materials of the bed according to their specific gravites by vibrating the table and 'by forcing air through the bed, discharging the lighter and heavier separated materials from the bed at different places and imposing mechanical resistance and rearwardly directed air currents at the place of discharge oi the heavier material to regulate said discharge.

13. The method of discharging a settled heavier material from a stratified bed of materials of different specific gravities which comprises vibrating the bed to intermittently advance the, settled heavier material and regulating the discharge thereof by air and regulable mechanical pressure.

14. An apparatus for discharging a settled heavier material from a stratied bed of materials of diierent specific gravities including in combination a discharge orifice, means for progressing a stream of settled heavier material to the oriiice, means for varying thev size of the orifice and a yielding member for normally closing the orifice.v n

l5. An apparatus for discharging a settled heavier material from a stratified bed oi matcrials of different specific gravities including in. combination a discharge orifice, means for progressing a. stream of settled heavier material to the orifice by intermittent advancing movement, means for varying the size of the orifice and a swinging closing member at the orifice adapted to swing open under impact of the advancing material to discharge the material.

i6. An apparatus for discharging a settled heavier material from a stratified bed of materials oi different specific gravities including in combination a discharge orifice, means for progressing a stream of settled heavier material to the orifice by intermittent advancing movements, means for directing air currents through the stream of materials counter to the direction of advance to prevent remixing of lighter material, and a closing member at the orice adapted to open Linder impact of the advancing material to discharge the material.

17. An apparatus for discharging a settled heavier material from a stratified bed of materials of different specc gravities including in combination a channel for the passage oi the in ferior heavier material, a variably positionable member for varying the height of the channel, and a swinging gate at the end of the channel for regulating the discharge of material therefrom.

18. The process oi separating intermixed divided materials which comprises stratifying a bed of said materials by air currents and vibration, progressing a stream of settled heavier material through a discharge oriiice, progressing a flotant, superposed stratum oi lighter material above the orice to discharge in a different direction, and

controlling the entry of material into the orifice by directing a current oi air through the orifice counter to the entering stream of heavier material and by varying the vertical extent of the orifice to hold back the superposed stratum of lighter material.

19. A mechanism for separating interinixed divided materials including in combination a vibratable, air-pervious table, means for maintain ing thereon a bed of intermixed materials of sub- ,y

stantial depth, means for stratifying the materials in superposed strata according to their specic gravities, means for progressing a settled stream of heavier material along the table sur-1 i ace to discharge, means for flowing the superior i stratum of lighter material transversely above the settled heavier material, and means for controlling the discharge of the stream of heavy material comprising an orice extending upwardly from the table surface and limited in its vertical and lateral dimensions, means for varying the height of the orifice to hold back the superposed lighter material and permit only the stratum of heavy material to pass therethrough, and means for passing a current of air through the orifice to oppose entry of lighter material and control the passage oi the heavy material.

2i). A mechanism for separating intermixed divided materials including in combination a. reciprocable, air-pervious table, means for maintaining and stratiiying thereon a bed of said materials, means for progressing a settled stream of heavier material along the table to discharge, means for progressing a ilotant stratum of lighter material transversely above the settled stream to discharge, a discharge orifice for the settled stream of heavy material and means for controlling passage of the heavier material through the orifice comprising a freely suspended closure adapted to oscillate by its own inertia during reciprocation of the table, and variable positionable means for controlling the depth of the orice.

2l. The method of discharging a settled heavier material from a forwardly and downwardly inclined, stratified bed of materials of different spe- Cif-lc gravities which comprises vibrating the bed to intermittently advance the settled heavier material' longitudinally of and to the forward end of the bed, and regulating the discharge thereof from the forward end of the bed by air and regulable mechanical pressure, the mechanical pressure opposing said discharge and being intermittently exceeded by pressure resulting from the accumulation of the heavier material to be discharged.

22. The method of discharging a settled heavier material from a forwardly and downwardly inclined stratified bed of materials of different specific gravities which comprises vibrating the stratified bed to intermittently advance a settled heavier material to the bottom and forward end of the bed, arresting the forward flow of a part of the forward end of said bed adjacent the lower portion of a superior stratum of lighter material and the upper portion of an inferior stratum of heavier material, permitting flow of the heavier settled material forwardly below said barrier, and regulating the discharge thereof by air and regulable mechanical pressure, the mechanical pressure opposing said discharge and being intermittently exceeded by pressure resulting from .accumulation of the heavier material to be discharged.

23. The method of discharging a settled heavier material from aforwardly and downwardly inclined, stratified bed of iaterials of different specific gravities which comprises vibrating the bed to intermittently advance the settled heavier material longitudinally of and to the forward end of the bed, and regulating the discharge thereof from the forward end of the bed by air and regulable mechanical pressure, including the steps of opposing the discharge of settled heavy material by said mechanical pressure to build up an accumulation of heavy material at the forward end of the bed until the combined pressures of the accumulated heavy material and airpressure existing in the bed overcome said mechanical pressure and release settled heavy material .from the bed.

24. The method of discharging a settled heavier material from a forwardly and downwardly inclined, stratied bed oi materials of different specilic gravities which comprises vibrating the bed to intermittently advance the settled heavier material longitudinally of and to the forward end of the bed, and regulating the discharge thereof from the forward endof the bed by air and regulable mechanical pressure, including the steps of interposing a barrier between'the upper part of the stratum of settled heavy material andthe lower part of the stratum of flotant lighter material, permitting flow of settled heavy material forwardly below said barrier and opposing discharge thereof by said mechanical pressure to build up an accumulation of heavy material vat the forward end of the bed and back into the bed behind the barrier until the pressure caused by the accumulation of saidheavy material overcomes the mechanical Ypressure to release settled heavy material from the bed.

KENNETH DAVIS. 

